A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

A hidden piece of Altoona's railroad history in a long-forgotten abandoned town.

The ruined remains of a coal mining ghost town are hidden within the woods.

This secluded walking trail is a hidden gem of a Pittsburgh park.

An eccentric priest's tribute to George Washington, this chapel tells the story of the American Revolution.

Locals call this magical moss-covered walkway the "Emerald Path."

For decades, it has disappeared and reappeared as water levels rise and fall.

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

World's first "penitentiary," meant to be humane, drove men insane.

The ruins of a fairytale castle with a tumultuous history stand high atop the mountains.

Once part of an ancient international harbor, it's now an all-you-can-eat shrimp buffet for flamingos and other water birds.

Breathtaking Byzantine paintings cover the inside of this 12th-century church.

An ancient necropolis of magnificent tombs.

The water here is so clear you can see the mysteriously sunken ship from the surface.

This hidden gem is bathed in beautiful natural light.

This Turkish cave boasts some rather bizarre associations with the King of Mount Olympus.

A mysterious ancient cemetery with Roman sarcophagi and Lycian inscriptions.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.

Flames have been burning within this mountain for more than 2,500 years.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

Roman ruins, natural methane fires and a lovely beach.

Live a night as a Byzantine King, with a minibar and private jacuzzi.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.